Management of maize lethal necrosis disease through hand weeding and insecticide applications at Arba Minch in Southern Ethiopia

• Main Authors: Getachew Gudero Mengesha, Biruk Kedir Mohammed, Keyredin Sultan Salo
• Format: Article
• Language: English
• Published: Taylor & Francis Group 2019-01-01
• Series: Cogent Food & Agriculture
• Subjects: audpc; insecticide; insect; mln; hand weeding; severity; weed
• Online Access: http://dx.doi.org/10.1080/23311932.2019.1705746

Maize lethal necrosis (MLN) is considered an important constraint of maize production in Ethiopia and particularly in southern part of the country. The study was conducted during 2016 and 2017 main cropping seasons to (i) determine the effect of hand weeding and insecticide application against MLN and yield and yield related attributes of maize; and (ii) to determine the economy of additional costs used for the management of MNL. The treatments such as hand weeding, only insecticide applied, hand weeding in combination of insecticide application (HW + InA) and unmanaged were arranged in randomized complete block design with five replications. Results showed that MLN severity was highly significant (p < 0.001) different both during 2016 and 2017 cropping seasons. It was varied among the treatments and between cropping years. In the two years, it was highest on unmanaged plots with 66.33% in 2016 and 56.33% in 2017. This might have been due to severe insect and weed infestation during the growing period over the evaluated plots. Conversely, the lowest MLN severity was recorded on the HW + InA with the value of 26.67% in 2016 and 25.00% in 2017 cropping season. Thus, severity was reduced by 62.31% in 2016, and 52.65% in 2017 in this treatment. As such not much difference in the area under disease progress curve (AUDPC) was observed in the two years. However, in both cropping seasons the lowest (15.96% and 15.01%-days, respectively) mean amount of AUDPC was recorded from plots managed with HW + InA. In 2016 and 2017 cropping seasons, HW + InA proved to be an effective against MLN management and gave the highest yields (4.89 and 5.84 t ha−1, respectively) over the unmanaged (1.06 and 1.39 t ha−1, respectively). Overall, results showed HW + InA was found to be better management option and reduced MLN and increased grain yields. Thus, it is better, as compared to other treatments, to use management option as it gave the relatively higher defense against MLN. However, further studies have to be undertaken in different agro-ecologies elsewhere in Ethiopia for developing solid advice on behalf of stabilizing maize production. Moreover, further research is warranted to confirm the role of insect pests and weeds as vector and alternative hosts, respectively for MCMV, SCMV, MDMV and WSMV causing MLN.